|Publication number||US5054064 A|
|Application number||US 07/501,688|
|Publication date||Oct 1, 1991|
|Filing date||Mar 29, 1990|
|Priority date||Mar 29, 1990|
|Publication number||07501688, 501688, US 5054064 A, US 5054064A, US-A-5054064, US5054064 A, US5054064A|
|Inventors||Stephen S. Walker, Clarence M. Sidlo, Melvin J. Teare|
|Original Assignee||Gte Laboratories Incorporated|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (3), Referenced by (94), Classifications (15), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
U.S. patent application Ser. No. 07/501,620, now abandoned, filed the same date as this, for Video Control System Having Billing Capability is concerned with video control systems having fication data and program identification data.
U.S. patent application Ser. No. 07/501,685, now abandoned, filed the same date as this, for Video Control System Having Terminal Specific Encryption Key is concerned with video control systems having a terminal specific encryption k
U.S. patent application Ser. No. 07/501,684, now U.S. Pat. No. 4,991,200, issued Feb. 5, 1991 filed the same date as this, for Video Control System Having Session Encryption Key is concerned with video control systems having a session encryption key.
U.S. patent application Ser. No. 07/501,683, now U.S. Pat. No. 5,046,090, issued 9/3/91, filed the same date as this, for Recorded Medium For Video Control System is concerned with video media for use with such systems.
U.S. patent application Ser. No. 07/501,682, now U.S. Pat. No. 5,046,092 issued 9/3/91, filed the same date as this, for Video Control System For Transmitted Programs is concerned with video control systems wherein the video program is transmitted to a terminal.
This invention is concerned with video control systems and more particularly is concerned with such systems using video recording storing a video program.
It is desirable to provide a video control system which decrypts encrypted broadcasts or recorded copies of video material such that the subsequent viewing is controlled. This allows the owner to either forbid viewing, or collect revenue at his or her discretion.
In the prior art, a software distribution system is known wherein a computer program is downloaded once, followed by an access key to allow use of it on each subsequent use. This system uses a dynamic key that constantly changes, and is directly related to an user's decoder box, both by ID and an internal dynamic counter.
Also known is a video system that autonomously controls the viewing of a recording for either 24 hours or once only. It does not have the power of control desired.
Briefly, a video system includes a central facility and a terminal. Means are provided for playing a video recording medium storing a video program including a series of television fields including a first field containing both a random digital code encrypted according to a code encryption key and program identification data, and a second field containing an unintelligible video signal previously transformed from an intelligible video signal according to the random digital code. The terminal includes means for sending the program identification data to the central facility. The central facility includes a data base for storing and retrieving at least one code encryption key corresponding to the program identification data and means for sending the code encryption key from the central facility to the terminal. The terminal further includes means for receiving the code encryption key from the central facility, decrypting means for decrypting the encrypted digital code of the first frame in accordance with the code encryption key, and means for transforming the unintelligible video signal of the second frame to the intelligible video signal using the decrypted random digital code.
FIG. 1 is a block diagram of a video system embodying the invention; and
FIG. 2 shows an encryption arrangement according to the invention.
Reference is made to FIG. 1 which is a block diagram of a video system 10 embodying the invention. The video system comprises a central facility 11, a terminal 12, and a duplex communication link 13 between central facility 11 and terminal 12. An overview of the system is first given.
Terminal 12 is provided with a video program including a series of television fields including first field containing both a random digital code encrypted according to a code encryption key and program identification data, and a second field containing an unintelligible video signal previously transformed from an intelligible video signal according to the random digital code.
The video program may be transmitted by broadcast, cable, satellite, fiber, or any other transmission medium 14. Alternative the video program may be stored on a video recording medium 15 such as magnetic tape or video disk and played by player 16. The unintelligible video signal may be either analog or digital.
A second field containing both a random digital code encrypted according to a code encryption key and program identification data, and is followed according to a third field containing an unintelligible video signal previously transformed from an intelligible video signal according to the random digital code of the second field.
Terminal 12 includes means 17 to store terminal identification data and means to send to the central facility 11 the terminal identification data and the program identification data over link 13.
Central facility 11 includes a data base 19 for storing and retrieving at least one code encryption key corresponding to the program identification data, means 20 for sending the code encryption key from the central facility 11 to the terminal 12, and means 21 for generating billing data based on both terminal identification data and program identification data.
Terminal 12 further including means 22 for receiving the code encryption key from central facility 11, decrypting means 23 for decrypting the encrypted random digital code of the first frame in accordance with the code encryption key, and means 24 for transforming the unintelligible video signal of the second frame to the intelligible video signal using the decrypted random digital code.
Each terminal 12 may have a terminal specific encryption key and means 18 to send to the central facility the program identification data and the terminal 11 identification data encrypted according to the terminal specific encryption key. The central facility 11 has means for storing a duplicate of the terminal specific encryption key, means for encrypting the code encryption key according to the terminal specific encryption key; and means for sending the encrypted code encryption key from central facility 11 to terminal 12.
Terminal 12 further includes means 22 for receiving the encrypted code encryption key from central facility 11, decryption means 23 for decrypting the code encryption key according to the terminal specific encryption key, and decrypting the encrypted random digital code of the first frame in accordance with the code encryption key, and means 24 for transforming the unintelligible video signal of the second frame to the intelligible video signal using the decrypted random digital code.
Terminal 12 includes means to encrypt the terminal identification data according to the terminal specific encryption key, means to send unencrypted terminal identification data and encrypted terminal identification data to the central facility, which in turn includes means to compare unencrypted and encrypted terminal identification data to verify terminal identity.
A plurality of code encryption keys may be used for one program wherein a desired code encryption key is selected from the plurality of code encryption keys in accordance with code encryption key identification data corresponding to the random digital code.
Various features of the system are now discussed in more detail.
System 10 controls the viewing of video programs, by which is meant any video material, either transmitted or recorded, in television format consisting of a series of fields of lines. Two interlaced fields make up a television frame.
Video programs are rendered unintelligible, e.g. scrambled, by any analog or digital method, and are made intelligible, e.g. descrambled , using random digital codes located in fields. The random digital keys are themselves encrypted and decrypted by a one or more key obtained from a database located at the central facility, along with user-specific information at the time of viewing. The system does not stop copying, it controls viewing, while protecting revenues. As such, it can encourage copying, which could ease the distribution issue by controlling the playback such that revenue can be collected each time.
Preferably duplex communication link 13 is a continuous data channel between a terminal and a central facility such as an ISDN D-channel or by modem a regular phone line.
The video program is encrypted, and needs a decrypter in the terminal for viewing. The decrypter uses data embedded in the video program along with a data access to correctly perform the decryption, so the process is completely controlled. The embedded data and key transfer from the remote database may be protected with public domain encryption techniques, providing high level security before first viewing.
The video program may be recorded as is, but it is still unviewable. To view it, the decrypter is used, along with the encrypted embedded data, and an access to a secure database, to perform the decryption. Recordings may be freely copied, but remain unviewable unless used with the decrypter.
To view the programs requires access to the database using encrypted data transfer. This process yields the control of the video program, whether recording or transmission. The decrypter requires one or more keys that arrives from the database. To get the key, information from the video program as well as terminal identification is sent to the database.
A direct Electronic funds Transfer (EFT) debit can be performed using the information. It the program is a video store copy, the EFT could include the store fee and the copyright fee. Note that the video distribution to video stores becomes trivial, as they are encouraged to take a direct recording with a video store key, along with their authorized converter box, and make as many copies as they like. The revenue control takes place at viewing time. This encourages a shareware type of distribution.
A passkey can be sent to the database, to allow viewing of questionable taste films by adults, controlling access by minors.
On the first access, the database will capture a signature derived from the user's equipment and the recording, and store it for subsequent tracking. As there is a compelled database access in this process, data on usage may be collected. This same process may be used for revenue collection.
The system preferably uses at least one downloadable key, a encrypted video program that uses the key for decryption, and data stored a field of the video program. It may be implemented in an all digital, analog or mixed analog/digital environment.
The video programs are encrypted, with data relating to the programs, e.g. where and when, who transmitted it. The data may also contain part of the decryption key. This information would be extracted from the signal, and used to access a database, maintained by the program's owners, to obtain an encrypted key for the decrypter. After a subscriber and/or a credit check is successfully completed, the one or more keys would be transmitted. At this time the owner has obtained usage data, with a specific user's ID, and has the option of billing him. If it is a free program, at least the viewer data is available.
If a user records a transmission or another recording, he captures the encrypted signal, along with embedded data, as described above. This accomplishes the signature part of the process. A recording created by this method may be on a regular VCR, but is encrypted and individually marked. Copying a recording does not affect the system, as the rerecording is only usable with the correct keys. Potentially, the first few minutes of a program might be viewable without the need of a key, to allow the user to see what the contents of the program are, as well as to allow time for the database access and key synchronization process.
To play a recording back, it is necessary to re-obtain the one or more keys. The combination of data stored in a field is used to access the database. Before the keys are made available, there is a check that the terminal identification and the embedded data match.
In the case wherein a recording is rented from a video store, a code may identify the store. The database recognizes the recording as a rental copy, and charge either the user or the video store a fee. If the recording is viewed a second time, the charge is repeated. In the event a copy is made, when it is played, the database will identify the originating video store, but not the actual copier. However, if validation is performed at rental time, there would be some measure of control. If the entire charging process were to be reversed, such that the viewer carries all the liability for charges, then copying is encouraged, as per shareware, and the distribution problem is minimized, while revenues are maintained on a usage basis.
The program's owner has the responsibility to get a secured copy to whoever deals with the distribution of the programs The programs are encrypted, and require a database update to enable viewers to make use of the program. The viewer has a terminal including a decrypter, linked to the central facility's database via an automatic dial-up, that, when enabled, decrypts the video program. As appropriate, there can be credit checks and billing from the database, as well as statistics collection.
The encryption has two levels, one for protection of video decryption codes on the program, and one for protection of messages between the terminal and the central facility. Both may use the NBS Data Encryption Standard (DES).
DES encryption and decryption may be implemented with a commercial Motorola 6859 Data Security Device or similar product at the terminal and at the central facility.
The decryption code itself is protected by being DES-encrypted. The decryption key is not on the video program but is retained in the database at the central facility. A program identification number and a decryption key number allow the central facility to recover the decryption key itself and send it to the terminal for decrypting the decryption codes.
A different DES decryption key is not required for every field. One key can span several fields. DES key requests and acknowledgements from the terminal may also act as keep-alive messages to the central facility.
DES decryption keys are transmitted from the central facility to the terminal protected by a higher-level DES "session" key terminal requests for new keys as the tape progresses are also protected by the DES session key. This key is generated by the central facility at the beginning of the session and remains valid for the duration of the session. The terminal begins the session using a terminal-unique DES key stored in a ROM.
Frame contents are transferred from the Analog Subsystem to the DCSS and the decrypted decryption code from the DCSS to the Analog Subsystem over the analog interface shown in the Figure. Transfer of data between the subsystems may be coordinated by means of the vertical and horizontal blanking signals and their derivative interrupts.
All messages between terminal and central facility use Cyclic Redundancy Code (CRC) checking to verify message integrity. The CRC-CCITT generating polynomial generates two block check characters (BCC) for each message. If the terminal receives a message that is not verified by the BCC, it sends a request (ARQ) to the central facility to retransmit the last message. The central facility does not attempt to ARQ garbled messages. It discards them and waits for a terminal to send again.
Message exchange in the VCS is by a positive acknowledgment scheme in which a response of some kind is expected for every message sent. For example, a terminal expects a DES decryption key message after it sends a request for the same; the central facility expects a key receipt acknowledge after it sends the key message.
When a user begins to play a protected program, the terminal initiates a session by sending a "session start" message (STS) to the central facility containing user and program identifications. The message contains message type, user number and CRC code in the clear, but the balance of the message is DES-encrypted with the initial DES session key stored in the terminal ROM. (The user identification is also stored in ROM.) The central facility uses the unencrypted data to access its database and find the user DES value for decrypting the remainder of the message.
The central facility authenticates the message by comparing clear and decrypted user numbers. If the user numbers are identical, the central facility then confirms that the program serial number is valid. The central facility may also check user credit. If all is well, the central facility accepts the session and generates a new (and random) DES key that is unique for that session. It encrypts this using the initial user value in the database and sends it to the terminal, which decrypts the message and stores the new value in its database (MCU RAM) as the session key for the remainder of the session.
The central facility then uses the tape and decryption key number in the STS message to recover a set of DES decryption keys for the program from the database. These are encrypted with the session key and sent to the terminal at the start of a session or during the course of a session.
The terminal generates session start, key acknowledgement, and ARQ messages. The central facility responds in kind. Both the central facility and the terminal generate and verify block check characters.
The preferred embodiment and best mode of practicing the invention have been described. Alternatives now will be apparent to those skilled in the art in light of these teachings. Accordingly the invention is to be defined by the following claims and not by the particular examples given.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4567512 *||Sep 28, 1983||Jan 28, 1986||World Video Library, Inc.||Recorded program communication system|
|US4595950 *||Dec 17, 1984||Jun 17, 1986||Loefberg Bo||Method and apparatus for marking the information content of an information carrying signal|
|US4635112 *||Feb 24, 1984||Jan 6, 1987||Sony Corporation||Method and apparatus for recording scrambled television signals|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US5146495 *||Oct 18, 1991||Sep 8, 1992||Gold Star Co., Ltd.||Circuit and method for maintaining security of video tape using privacy number|
|US5509070 *||Dec 15, 1992||Apr 16, 1996||Softlock Services Inc.||Method for encouraging purchase of executable and non-executable software|
|US5761302 *||Nov 22, 1995||Jun 2, 1998||Lg Electronics Inc.||Copy prevention method and apparatus for digital video system|
|US5796828 *||Jul 7, 1995||Aug 18, 1998||Sony Corporation||Controlled-access broadcast signal receiving system|
|US5897218 *||Jun 2, 1997||Apr 27, 1999||Hitachi, Ltd.||Signal recording/reproducing method and apparatus in which key information for descrambling is recorded in an area on the signal recording medium|
|US6021197 *||Jun 18, 1996||Feb 1, 2000||Irdeto B.V.||Method and apparatus for controlling the operation of a signal decoder in a broadcasting system|
|US6028932 *||Apr 1, 1998||Feb 22, 2000||Lg Electronics Inc.||Copy prevention method and apparatus for digital video system|
|US6055314 *||Mar 22, 1996||Apr 25, 2000||Microsoft Corporation||System and method for secure purchase and delivery of video content programs|
|US6105134 *||Jul 31, 1998||Aug 15, 2000||Scientific-Atlanta, Inc.||Verification of the source of program information in a conditional access system|
|US6347144||Feb 3, 2000||Feb 12, 2002||Lg Electronics Inc.||Copy prevention method and apparatus for digital video system|
|US6385317||Mar 21, 1997||May 7, 2002||Irdeto Access Bv||Method for providing a secure communication between two devices and application of this method|
|US6393128||Aug 31, 1999||May 21, 2002||Mindport B. V.||System for broadcasting data signals in a secure manner|
|US6751598 *||Jul 2, 1997||Jun 15, 2004||Hitachi, Ltd.||Digital content distribution system and protection method|
|US6766024||Aug 31, 1999||Jul 20, 2004||Mindport B.V.||Data communication system|
|US7062048||Feb 18, 2003||Jun 13, 2006||Wegener Communications, Inc.||Apparatus and method for single encryption with multiple authorization of distributed content data|
|US7065508||Aug 20, 2004||Jun 20, 2006||Sl Patent Holdings Llc||System and method for operating a licensing server|
|US7085743||Sep 30, 2004||Aug 1, 2006||Sl Patent Holdings Llc||System and method for creating and running protected information|
|US7089212||May 21, 2004||Aug 8, 2006||Sl Patent Holdings Llc||System and method for controlling access to protected information|
|US7092908||Nov 12, 2004||Aug 15, 2006||Sl Patent Holdings Llc||System and method for selling protected information in an oem context|
|US7158954||Oct 27, 2004||Jan 2, 2007||Sl Patent Holdings Llc||System and method for processing protected video information|
|US7171553||Mar 18, 2002||Jan 30, 2007||Irdeto Access B.V.||Method for providing a secure communication between two devices and application of this method|
|US7191898||Aug 24, 2004||Mar 20, 2007||Union Rich Usa, Llc||Saw blade case|
|US7209901||Aug 29, 2001||Apr 24, 2007||Sl Patent Holdings Llc C/O Aol Time Warner||Method for selling, protecting, and redistributing digital goods|
|US7249103||Dec 30, 2004||Jul 24, 2007||Sl Patent Holdings, Inc.||System and method for selectively enabling access based on lineage analysis of digital information|
|US7319988||Oct 20, 2004||Jan 15, 2008||Sl Patent Holdings Llc||System and method for processing protected audio information|
|US7353205||Dec 30, 2004||Apr 1, 2008||Sl Patent Holdings Llc||Method for causing a digital product to revert to a demo mode|
|US7353207||Dec 15, 2004||Apr 1, 2008||Sl Patent Holdings Llc||Method of altering a software product in response to predetermined events|
|US7555463||Nov 13, 2006||Jun 30, 2009||Sl Patent Holdings Llc||System and method for selectively changing parameter settings based on lineage analysis of digital information|
|US7787752 *||Aug 17, 2001||Aug 31, 2010||Sony Corporation||Information processing apparatus and method, and recording medium|
|US7831516||Dec 6, 2006||Nov 9, 2010||Sl Patent Holdings Llc||System and method for redistributing and licensing access to protected information among a plurality of devices|
|US7962417||Sep 30, 2004||Jun 14, 2011||Sl Patent Holdings Llc||System and method for distributing protected information|
|US8140435||Nov 4, 2004||Mar 20, 2012||Sl Patent Holdings Llc||System and method for processing protected text information|
|US8332328||Jun 23, 2010||Dec 11, 2012||Sl Patent Holdings Llc||System and method for redistributing and licensing access to protected information among a plurality of devices|
|US8352373 *||Jan 28, 2003||Jan 8, 2013||Intarsia Software Llc||Data copyright management system|
|US8448254||Nov 1, 2010||May 21, 2013||Intarsia Software Llc||Digital content management system and apparatus|
|US8554684||Jul 11, 2011||Oct 8, 2013||Intarsia Software Llc||Controlling database copyrights|
|US8571629||Nov 13, 2007||Oct 29, 2013||Truth Test Technologies, Llc||Detection of deception and truth-telling using fMRI of the brain|
|US8595502||May 25, 2006||Nov 26, 2013||Intarsia Software Llc||Data management system|
|US9245260||Aug 29, 2006||Jan 26, 2016||Xylon Llc||Data copyright management|
|US20020057900 *||Aug 17, 2001||May 16, 2002||Yasuhisa Nakajima||Information processing apparatus and method, and recording medium|
|US20020126844 *||Mar 18, 2002||Sep 12, 2002||Rix Simon Paul Ashley||Method for providing a secure communication between two devices and application of this method|
|US20040158707 *||Feb 9, 2004||Aug 12, 2004||Samsung Electronics Co., Ltd.||Mobile terminal for use restriction and copyright protection for content, and content security system using the same|
|US20040215571 *||May 21, 2004||Oct 28, 2004||Jonathan Schull||System and method for controlling access to protected information|
|US20050021473 *||Aug 20, 2004||Jan 27, 2005||Jonathan Schull||System and method for operating a licensing server|
|US20050039026 *||Sep 30, 2004||Feb 17, 2005||Jonathan Schull||System and method for creating and running protected information|
|US20050060265 *||Oct 27, 2004||Mar 17, 2005||Jonathan Schull||System and method for processing protected video information|
|US20050102239 *||Nov 12, 2004||May 12, 2005||Jonathan Schull||System and method for selling protected information in an oem context|
|US20050149444 *||Dec 30, 2004||Jul 7, 2005||Jonathan Schull||Method for tracking software lineages|
|US20050149451 *||Dec 30, 2004||Jul 7, 2005||Jonathan Schull||Method for tracking software lineages|
|US20080221812 *||Sep 27, 2007||Sep 11, 2008||Richard Pittaro||Differentiation of flow cytometry pulses and applications|
|US20090030879 *||Jul 26, 2007||Jan 29, 2009||The Directv Group, Inc.||Method and system for performing multi-level program guide category searches|
|US20090031369 *||Jul 26, 2007||Jan 29, 2009||The Directv Group, Inc.||Method and system for ordering video content from an interactive interface|
|US20100099975 *||Nov 13, 2007||Apr 22, 2010||Truth Test Technologies, Llc||Detection of deception and truth-telling using fmri of the brain|
|US20110047626 *||Nov 1, 2010||Feb 24, 2011||Makoto Saito||Digital content management system and apparatus|
|USRE38007 *||Aug 17, 2000||Feb 25, 2003||Sony Corporation||Controlled-access broadcast signal receiving system|
|USRE38898 *||Dec 19, 2002||Nov 29, 2005||Sony Corporation||Video data bus communication system and method|
|USRE39319 *||Dec 17, 2003||Oct 3, 2006||Lg Electronics Inc.||Copy prevention method and apparatus for digital video system|
|USRE40468||Nov 28, 2005||Aug 26, 2008||Sony Corporation||Video data bus communication system and method|
|USRE41074||Jan 24, 2005||Jan 12, 2010||Lg Electronics Inc.||Copy prevention method and apparatus for digital video system|
|USRE41709||May 20, 2008||Sep 14, 2010||Sony Corporation||Controlled-access broadcast signal receiving system|
|USRE41919||Apr 16, 2009||Nov 9, 2010||Steve Olivier||Rapid decryption of data by key synchronization and indexing|
|USRE42921||Aug 2, 2004||Nov 15, 2011||Lg Electronics Inc.||Copy prevention method and apparatus for digital video system|
|USRE42922||Jan 24, 2005||Nov 15, 2011||Lg Electronics Inc.||Copy prevention method and apparatus for digital video system|
|USRE42950||Dec 17, 2003||Nov 22, 2011||Lg Electronics Inc.||Copy prevention method and apparatus for digital video system|
|USRE42951 *||Nov 5, 2004||Nov 22, 2011||Lg Electronics Inc.||Copy prevention method and apparatus for digital video system|
|USRE43993||Jul 17, 2007||Feb 12, 2013||Lg Electronics Inc.||Method and apparatus for scrambling and/or descrambling digital video data and digital audio data using control data|
|USRE44068||Jul 17, 2007||Mar 12, 2013||Lg Electronics Inc.||Method and apparatus for descrambling digital video data and digital audio data using control data|
|USRE44106||Jan 7, 2009||Mar 26, 2013||Lg Electronics Inc||Copy prevention method and apparatus of a digital recording/reproducing system|
|USRE44121||Jan 7, 2009||Apr 2, 2013||Lg Electronics Inc.||Copy prevention method and apparatus of a digital recording/reproducing system|
|USRE44952 *||Dec 16, 2002||Jun 17, 2014||Sony Corporation||Controlled-access broadcast signal receiving system|
|CN1567993B||Nov 26, 1995||Mar 28, 2012||Lg电子株式会社||Copy prevention method and apparatus|
|CN1822667B||Nov 26, 1995||Mar 12, 2014||Lg电子株式会社||Copy prevention method and apparatus|
|EP0684721A3 *||May 23, 1995||Aug 19, 1998||Sony Corporation||Data bus communication|
|EP0691787A1 *||Jul 6, 1995||Jan 10, 1996||Sony Corporation||Receiving controlled-access broadcast signals|
|EP0975165A2 *||Jul 6, 1995||Jan 26, 2000||Sony Corporation||Receiving controlled-access broadcast signals|
|EP0975165A3 *||Jul 6, 1995||Dec 20, 2000||Sony Corporation||Receiving controlled-access broadcast signals|
|EP0984590A2 *||May 23, 1995||Mar 8, 2000||Sony Corporation||Data bus communication|
|EP0984590A3 *||May 23, 1995||Jun 22, 2005||Sony Corporation||Data bus communication|
|EP1126705A3 *||Jul 6, 1995||Mar 6, 2002||Sony Corporation||Receiving controlled - access broadcast signals|
|EP1244306A2 *||Jul 6, 1995||Sep 25, 2002||Sony Corporation||Receiving controlled-access broadcast signals|
|EP1244306A3 *||Jul 6, 1995||Jun 2, 2004||Sony Corporation||Receiving controlled-access broadcast signals|
|EP1461950A1 *||Dec 13, 2002||Sep 29, 2004||Sony Electronics Inc.||Decoding and decryption of partially encrypted information|
|EP1461950B1 *||Dec 13, 2002||Mar 9, 2016||Sony Electronics, Inc.||Decoding and decryption of partially encrypted information|
|EP1737184A2 *||May 23, 1995||Dec 27, 2006||Sony Corporation||Data bus communication|
|EP1737184A3 *||May 23, 1995||Jan 24, 2007||Sony Corporation||Data bus communication|
|EP1737185A2||May 23, 1995||Dec 27, 2006||Sony Corporation||Data bus communication|
|EP1737185A3 *||May 23, 1995||Jan 24, 2007||Sony Corporation||Data bus communication|
|EP1808999A1 *||May 23, 1995||Jul 18, 2007||Sony Corporation||Data bus communication|
|EP1845527A2 *||Jul 6, 1995||Oct 17, 2007||Sony Corporation||Receiving controlled-access broadcast signals|
|EP1845527A3 *||Jul 6, 1995||Apr 25, 2012||Sony Corporation||Receiving controlled-access broadcast signals|
|EP1968058A2||Jul 6, 1995||Sep 10, 2008||Sony Corporation||Receiving controlled-access broadcast signals|
|EP1968058A3 *||Jul 6, 1995||Dec 21, 2011||Sony Corporation||Receiving controlled-access broadcast signals|
|EP1968059A3 *||Jul 6, 1995||Dec 21, 2011||Sony Corporation||Receiving controlled-access broadcast signals|
|EP2262200A3 *||May 23, 1995||Jan 26, 2011||Sony Corporation||Data bus communication|
|U.S. Classification||380/239, 380/241, 380/202, 348/E07.056, 380/231|
|Cooperative Classification||H04N7/1675, H04N21/2543, H04N21/472, H04N21/6581, H04N21/63345, H04N21/4405, H04N21/4334, H04N21/4325|
|Mar 29, 1990||AS||Assignment|
Owner name: GTE LABORATORIES INCORPORATED, A CORP. OF DE
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:WALKER, STEPHEN S.;SIDLO, CLARENCE M.;TEARE, MELVIN J.;REEL/FRAME:005266/0705
Effective date: 19900327
|Mar 31, 1995||FPAY||Fee payment|
Year of fee payment: 4
|Mar 12, 1999||FPAY||Fee payment|
Year of fee payment: 8
|Mar 31, 2003||FPAY||Fee payment|
Year of fee payment: 12
|Apr 23, 2007||AS||Assignment|
Owner name: VERIZON LABORATORIES INC., MASSACHUSETTS
Free format text: CHANGE OF NAME;ASSIGNOR:GTE LABORATORIES INCORPORATED;REEL/FRAME:019193/0372
Effective date: 20000630